Conventional ways to stop diesel engines include stopping the flow of fuel to the combustion chamber. In some cases, when the diesel engine enters a run-away state, a common method of stopping the engine includes removing the air supply to the combustion chamber. This can cause the combustion chamber to be deprived of oxygen, and thus quench the uncontrolled combustion. Therefore, engines employing shut-off mechanisms may employ safety valves that cut off the air supply so as to shut off the engine during such undesired situations.
Some large engine air systems may be designed such that two air shutoff valves may be needed. A reliable detection strategy is needed in applications that require emergency shutdowns by cutting off intake air and fuel to the engine. If this strategy is not in place, a user may run the risk of operating an engine with one shutoff valve open and the other shutoff valve closed, which may cause catastrophic engine failure.
Thus, ways have been developed to monitor the status of the shutoff valves. Conventionally, air shutoff monitoring has employed mechanical and magnetic based switch technology. However, mechanical components have a limited life span due to fatigue, wear, and other factors induced by a running engine. Also, in high vibration environments, mechanical and magnetic based switches are prone to failure, thereby rendering these types of switches unreliable. As one example, mechanical switches have shown a tendency to create false positive failures, sending a detection signal when nothing physically has happened. Also, such mechanical switches can be prone to sending false signals when paired with diesel engine vibration. Failure can also occur when air shutoffs trip and only one is reset.
As a result, conventional techniques of using, for example, mechanical and magnetic based switch technology in an air shutoff system and assembly have not been effective in preventing engine failures. It is therefore desirable to provide, among other things, an improved air shutoff system and method.